Do what I did a while ago:How do I know if the air shutters in front are correctly opening or closing? There's no indicator or DIC message.
Looking at a 2018+ OEM wiring diagram, I came across a LIN bus, it was labeled a shutter control. LIN is a two-way 1-wire communication bus, so the shutter should be reporting back it's actual position in this application. GM may also have a feedback-loop.If the shutters aren't operating correctly a check engine light will set.